This book surveys the recent advances in the field of ultrafast fiber switching devices and systems that have potential processing speeds in excess of 50 gigabits-per-second. The treatment covers basic physical principles, device physics and systems applications. The purpose of the book is to provide a complete tour of the key research issues and approaches in ultrafast switching. Topics covered include routing and logic devices, solitons in optical fibers, and the application of ultrafast gates to telecommunications transmission systems, local area networks and optical computing. The author is a member of the Technical Staff in basic research at AT&T Bell Laboratories, Holmdel, and is excellently positioned to provide this state-of-the-art survey in this exciting and advancing field. The book will be of great value to all researchers and graduate students working in the areas of high-speed electronics, optical data processing, nonlinear guided-wave optics, and photonic switching.